Ophthalmoscope.



F. A. WELCH.

OPHTHALMOSCOPE.

APPLICATION HLED MAR. 31, His.

Patented Dec. 28, 1915.

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FRANCIS A. winners, on NEW YORK, N. Y.

OPHTHALMOSCOPE.

Specification of Letters Patent.

Patented Ben. 28, 19915.

Application filed March 31, 1915. Serial No. 18,278.

To all whom it may concern:

Be it known that I, FRANoIs A. WnLoH, a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved Ophthalmoscope, of Which the following is a full, clear, and exact description.

This invention'relates to optical instruments and has particular reference to ophthalmoscopes.

Among the objects of the invention is to provide an instrument of the character indicated which is of a simple, compact and eflicient nature and adapted for the use of a lens-front lamp whereby a concentrated beam of light may be thrown directly along the line of sight of the observer closely parallel to the axis of the lamp and thereby avoiding the necessity for using a shade or hood to protect the observers eye, and also permit of the use of a suitable auxiliary lens or lenses in front of the lamp for further concentrating the beam of light or focusing for retinoscopy or shadow testing,

or for focal illumination.

Another object of the invention is to provide an ophthalmoscope in the practical operation of which a reflecting mirror is dispensed with.

A further object of the invention is to construct an ophthalmoscope having a lamp and peep hole closely adjacent the lamp, and a rotary lens disk havinga plurality of concentrically disposed series of lenses associated with the lamp and peep hole in such a'n anner as to shift the lens disk radially with relation to the lamp so as to bring any lens of either series within the line of sight. I

The foregoing and other objects of the invention will hereinafter be more fully described and claimed and illustrated in the drawings forming a part of this specification in which like characters of reference indicate corresponding parts in all the views, and in which- Figure 1 is'a front elevation of a preferred embodiment of this'invention; Fig. 2 is a rear elevation of the same; Fig. 3 is a rear elevation of the lens disk detached; Fig. 4 is a vertical, sectional view on the line t4: of Fig. 1; Fig. 5 is a side elevation of the same; and Fig. 6 is a rear elevation of the front shield.

lbs s eral part of device he ings, I show the principal parts of this invention which include a support for the lamp and lens mechanism, the latter mechanism comprising a rotary lens disk and front and rear shields therefor. Said support is indicated at QOand comprises a rigid shank of any suitable material or cross sectional construction and adapted to serve as a handle or as a means for attaching a suitable handle if desired. At the upper end the shank is provided with a peep hole 21 having an axis perpendicular to the length of the shank 20 and open from front to rear. Closely adjacent the peep hole is formed a socket 22 for an electric lamp 23 preferably of the type known as the lensfront. In other words, this lamp comprises a cylindrical base 24- screwed into the socket 2-2 and having a light-concentrating lens 25 at its front end, said lens being of a diameter substantially the same as that of the lamp base or shell. This lens 25, therefore, serves to concentrate or direct all the rays of light from the lamp forwardly in a beam parallel to the axis of the peep hole 21 and closely adjacent thereto. The observer at the rear of the instrument, therefore, receives no rays of light directly from the lamp into his own eye.

The form of lamp herein shown and described enables me to apply thereon an auxiliary shell or sleeve 26 carrying an additional focusing lens 27, said shell being telescopic or slidable lengthwise upon the main lamp shell. This auxiliary lens may be employed to vary the shape or effect of the light beam and is especially useful in the practice of retinoscopy or shadow testing.

The lens disk 28 is indicated in rear elevation in Fig. 3 as comprising a plurality of series of lens openings arranged concentrically with the central opening 29 of the disk which constitutes the center of rotation thereof. These series are shown as two in number indicated at 30 and 31, and the openings of both series being in radial alinement. In other words, the openings are ent r-abl s eas l th l e the series, and hence it is expedient to identify corresponding lenses of both series with a single series of identifying marks such as numerals shown in the drawings and indicated by the reference character 32. These identifying marks 32 also are preferably arranged concentrically with respect to the lens openings. The opening 31 may be without a lens, but all the others have lenses, those of oneseries being of a different character from these of the other, and the lenses of each series being graduated progressively as indicated by the nature of the identifying marks 32, all as will be well understood by one skilled in this art. The drawings in- I dicate the lens disk 28 as being composed of two plates connected together as by means of screws 33, but this feature of mechanicalstructure is not vital. The periphery of the disk also is preferably milled for convenience in controlling the rotary position thereof.

The improved supporting means for the disk 28 comprises a front shield 34 having a substantially central hub 35 projecting through the bearing hole 29 of the disk 28. This shield 33% is substantially of the same diameter as the disk 28 and guarding the same except at the points 3 1 where the periphery of the shield is cut away to provide access to the milled periphery of the disk 28. These cut-away portions are shown adjacent the low-er edge of the shield but obviously might be differently located if desired. Any

suitable means may be provided to retain the lens disk in place upon the hub 35, such means being indicated herein as comprising a rear shield 36 of substantially the same size and form as the front shield34: and

fitted upon a reduced neck 37 constituting a rearward extension of the hub A fastener 38 1s passed into the neck and hub and includes a head bearing against the central portion of the rear shield holding it in fixed position with respect to the other two parts. The rear shield is further held in fixed position by means of screws 39 extending into the lower edge thereof through lugs 40 ex tending laterally and circumferentially from 'a thumb piece 11 projecting rearwardly from the lower edge of the front shield 3st and through which the operator may manipulate the disk devices as a whole with respect to the lamp shank while holding the latter in his hand.

The rear shield 36 is provided with a radial series or row of holes shown as three 1n number and indicated as 30 31 and 32 corresponding to the two concentric rows of openings 30 and 31 and the circle of index characters 32, these shield holes being at the same distance from the axis of the disks as the said openings and index charlacters, the shield 36 being held in a-fixed positionWith-respect to said'axis. The characters of the series 32 are adapted to be read in succession through the hole 32 and at such time the corresponding plus and minus lenses are in registry with the other two holes, and one or the other will be in the line of vision through the hole 21, depending upon the position of the disk devices with relation to the shank. In this connection it will be noted that the front shield 31 is apertured so as to not (bStlUCt the vision through the hole 21 and the selective rear shield holes and lenses. The provision indicated for this purpose is a radial slot 3-1" of a length equal to the combined diameters of the holes 30 and 31.

Any suitable means may be provided to connect the shank with the disk devices for the purposes of the invention. I show for this purpose a bracket 4-2 secured as by screws as to the distal or front face of the front shield, said bracket having a vertical guideway in which the shank 20 is slidably fitted. The shank is held from lateral dis placement from the bracket by means of flanges ts, one of which is shown provided with a stud 4:5 snapping into one or the other of a pair of spaced recesses 4-6 to hold the disk devices in desired position temporarily, but with not so great a force as to prevent the sliding of the disk devices up or down while holding the shank in the hand. The sliding movement of the bracket along the shank is positively limited by studs 4-7 which strike against the upper and lower ends of the brackets in alternation.

I claim:

'1. In an ophthalmoscope, the combination of a shank, a lens-front lamp secured thereto with its axis at right angles to the length of the shank, said shank having a peep hole therethrough closely adjacent and parallel to the axis of the lamp, and adjustable lens devices mounted upon the shank and movable transversely with respect to the axes of the peep hole and lamp.

2. In an ophthalmoscope, the combination of a shank or support, a lens-front lamp secured in said shank and projecting forwardly therefrom, said lamp comprising a tubular base and a lens of substantially the same diameter as the base for concentrating the rays of light, said shank having a peep hole closely adjacent the lamp and having its axis closely parallel to the axis of the lamp, and lens mechanism fitted to and slidable upon the shank whereby the line of vision through the peep hole may coincide with any selective lens of the lens devices.

3. In an ophthalmoscope, the combination of a shank having a peep hole extending therethrough at a right angle to the axis of the shank, a lens-front lamp secured to the shank with its axis closely adjacent and parallel to the axis of the peep hole, a lens disk "having a plurality of concentric series of lenses, and means to support the lens disk upon the shank adapting it for rotation and slidable movement so as to bring any lens of either series into registry with said peep hole.

4. In an ophthalmoscope, the combination of astraight rigid support having a peep hole extending therethrough at an angle to the axis of the support, a lens-front lamp having a cylindrical base secured to its support and having its axis closely adjacent the axis of the peep hole, a focusing lens adjustably fitted upon the lamp, and rotarily and longitudinally adjustable lens devices mounted upon the support whereby any selective lens may be brought into registry with the peep hole.

5. In an ophthalmoscope, the combination of a straight rigid support having a peep hole therethrough, a lamp secured to the support closely adjacent said peep hole, a bracket slidable upon the support toward and from the lamp and peep hole, and a rotary disk journaled upon the bracket and slidable therewith longitudinally of the support, said disk being provided with a plurality of concentric circular series of lenses, said lenses being arranged in radial pairs.

6. In an opthalmoscope, the combination of a rigid support having a peep hole therethrough, a lens-front lamp arranged in said support closely adjacent the peep hole and having the axis of its rays parallel to the axis of the peep hole, a bracket slidably fitted upon the support, means to control and positively limit the sliding movements of the bracket, a lens disk having a plurality of circular series of concentric lenses, means to inclose and support said disk upon the bracket, and means to both rotate and slide the disk While the support is being held whereby any selective lens is brought into registry with said peep hole.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

FRANCIS A. WELCH.

Witnesses:

GEO. L. BEELER, PHILIP D. RoLLHAUs.

itopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

